Ovalbumin is a major egg-white protein and its systhesis in the chicken oviduct is induced by estrogen and progesterone. Recent studies have indicated that these steroid hormones regulate ovalbumin gene expression in the chicken oviduct mainly at the transcriptional level. Advances in recombinant DNA technology have made it possible to isolate, amplify and determine the detailed molecular structure and nucleotide sequence of this gene. The primary structure of the ovalbumin gene is among the most complex eucaryotic genes studied. It is 7.55 kilobase pairs in length to code for a mature messenger RNA of 1872 nucleotides. It contains seven intervening sequences of various sizes, separating the structural sequences into eight segments. With this well-defined gene in hand, our general objectives are to explore the molecular events involved in the expression of this gene after its re-introduction into a eucaryotic cell. This will be accomplished by utilizing our expertise in nucleic acid chemistry, recombinant DNA technology and in cell culture technology. Specifically, we wish to return the ovalbumin gene to an intracellular environment by DNA-mediate gene transfer and by SV40-hybrid transfection so that its expression in terms of transcription, RNA processing and protein synthesis can be accurately monitored. By comparing the normal expression of the ovalbumin gene with the expression exhibited by its mutants which are modified at specific locations by site-directed mutagensis, we wish to determine the relationship between gene structure and its functional consequence. It is our aim to pinpoint specific DNA regions on th gene that are involved in the initiation and termination of transcription, RNA processing as well as hormone responsiveness as a first step to gain a better understanding of eucaryotic gene expression and regulation.